An analysis of the psychometric properties of the medication safety competence scale in Turkish

Purpose Considering the key roles and responsibilities of nurses in ensuring medication safety, it is necessary to understand nurses’ competence in medication safety. Therefore, it was aimed to introduce a scale evaluating the medication safety competence of nurses into Turkish and to contribute to the literature by determining the medication safety competence levels of nurses. Methods A methodological and descriptive research design was utilised. The population consisted of nurses in Turkey, and the sample comprised 523 nurses who volunteered to participate. Results The content validity index of the scale was 0.98, and the scale showed a good fit (χ2/df = 3.00, RMSEA = 0.062). The Cronbach’s alpha coefficient of the scale was 0.97, indicating high reliability. The mean score was 4.12, which was considered high. Participants who were 40 years old or above, married, and graduates of health vocational schools or postgraduate programs, along with those who had received medication safety training, had higher medication safety competence scores. Conclusion This study presents strong evidence that the Turkish version of the Medication Safety Competency Scale is valid and reliable when administered to nurses. The participants in this study had high levels of medication safety competence. Supplementary Information The online version contains supplementary material available at 10.1186/s12912-024-02240-0.


Introduction
A medication error is defined as a preventable event at any stage of drug therapy that results in incorrect drug use or harms the patient [1].According to World Health Organization (WHO) reports, medication errors account for 20% of medical errors [2].Medication errors decrease multidisciplinary and multi-stage process.Nurses constitute the majority of the healthcare team and are involved in many stages of the medication administration process; they are at the centre of medication administration and are involved in the most critical stage when any potential errors reach the patient [7].
Traditional nursing curricula consider the "right principles" as a basic standard for safe medication practices.However, nurses' role in ensuring medication safety encompasses many other principles [3].Limiting nurses' responsibilities regarding medication safety to the right principles does not address all aspects of errors [8].Medication safety requires nurses to use clinical judgment before, during, and after interventions.Nurses' experience and knowledge are integral components of safe medication management in nursing practice [9].Adverse effects caused by improper prescription, administration, or monitoring of medications can be decreased through good nursing practice [8].
Considering the high prevalence of medication errors and the key role of nurses in ensuring medication safety, the medication safety competence of nurses must be determined [4].However, very few studies have assessed nurses' medication safety competence [3][4][5][6].Moreover, a Turkish scale to assess nurses' the of and attitudes towards medication safety competence is needed.
Therefore, this study introduced a Turkish version of a scale evaluating the medication safety competence of nurses and administered it to nurses, contributing to the literature by determining the medication safety competence levels of nurses.

Methods
This study adapted the Medication Safety Competence Scale (MSCS) developed by Park and Seomun (2021) for use in a Turkish context and assessed its validity and reliability; subsequently, the scale was used to determine nurses' the of medication safety competence [5].Differences in the of medication safety competence between nurses with varying demographic characteristics were also investigated.

Study design and participants
This study was conducted methodologically and descriptively.This study was structured and reported according to the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) checklist [10].
The population of the study comprised nurses working at various hospitals in Turkey.Convenience sampling method was used.The sample consisted of 523 nurses who were native Turkish speakers and voluntarily participated in the study.No one refused to participate in the study.There were no missing data except for 36 data related only to the worked clinic was conducted.However, these 36 data were not excluded; instead, analyses related to the clinic variable were conducted using 487 data (Tables 1 and 2).
The sample size for conducting CFA was determined to be at least 10 times the number of scale items [11].This rule was met for 36 items with 523 cases.In descriptive analyses, the sufficiency of the sample size was determined by a post hoc power analysis.As a result of the post hoc power analysis conducted with G*Power 3.1.9.7, the power of the study was calculated as 85% with an effect size of 0.26 and a significance level of 0.05 [12].

Data collection
A demographic information form was used to determine the demographic characteristics of the nurses, and the MSCS was used to determine their the of medication safety competence.The demographic information form consists of 10 questions.The form, which was prepared by the researchers in line with the literature, consists of questions with demographic characteristics of the nurses such as age, gender and worked clinics [3][4][5][6].
The MSCS was developed by Park and Seomun in 2021 [5]  ) and invited to participate in the online survey prepared through Google Forms.An informed consent form was attached to the first part of the questionnaire and participation was voluntary.The response time of the questionnaires was 8-10 min.

Procedure
This study was conducted in two stages: methodological and descriptive.

Methodological stage
This stage consisted of translation and psychometric testing.To adapt the scale for use in a Turkish context, permission was obtained from the researchers who developed the original scale.Back translation was used for language validity.The content validity of the Turkish version of the scale was tested.After receiving expert opinions, the scale was translated back into English (supplementary file-1).After the translated version was sent to the researchers who developed the scale and approval was obtained, data collection was started with the Turkish form.Data were then collected for psychometric testing.The validity and reliability of the original scale were tested with data from the 523 participants.

Descriptive stage
In this stage, nurses' the of medication safety competence were determined and analysed according to several demographic characteristics.Data from the 523 participants were used in this stage.

Data Analysis
Data were analysed with the Statistical Package for the Social Sciences (SPSS) v. 26.0, LISREL v. 8.80, and Microsoft Excel.

Descriptive statistics
Means and standard deviations were calculated for continuous data, and percentages were calculated for categorical data.The adequacy of the multivariate normal distribution of the data was assessed using Mardia's skewness and kurtosis tests.Mann-Whitney U and Kruskal-Wallis tests were used for comparison between groups of nurses with different demographic characteristics.

Item analysis
To determine whether the scale had an ideal discrimination ability, the total score of the scale was ranked from high to low, and the difference between the first 27% and the last 27% was analysed.Furthermore, item-total score correlation coefficients were calculated.

Validity analysis
Eleven experts rated the items of the adapted scale from 1 to 4 for content validity (1: not appropriate; 2: partially appropriate, the item needs to be revised; 3: appropriate but minor changes are needed; 4 very appropriate).The item content validity index (I-CVI) and the scale content validity index (S-CVI) were calculated using the method proposed by Davis (1992) [13].The I-CVI is the ratio of the number of experts who assign each item 3 or 4 points to the total number of experts.The S-CVI is the average I-CVI for all items.
Confirmatory factor analysis (CFA) was applied for the construct validity, and fit indices were evaluated.The values of chi-square (χ 2 )/degree of freedom (df ), comparative fit index (CFI), root-mean-square error of approximation (RMSEA), non-normed fit index (NNFI), normed fit index (NFI), standardised root mean square residual (SRMR), root mean square residual (RMR), goodness of fit index (GFI), and adjusted goodness of fit index (AGFI) were examined.Also average variance extracted (AVE) and Construct reliability (CR) were examined for convergent validity.

Reliability analysis
Cronbach's alpha (α) and split-half reliability were calculated to assess internal consistency.To assess test-retest reliability, intra-class correlation (ICC) was calculated by collecting data from 30 nurses at 2-week intervals.The data obtained for the test-retest were not included in the sample.

Ethical considerations
Ethical approval of the study was obtained from the Suleyman Demirel University Institutional Ethics Committee (decision number: 87432956-050.99-423263).Informed consent was obtained from the participating nurses in the first part of the online survey.The study was carried out in accordance with the principles of the Declaration of Helsinki.

Results
Most participants (94.5%) were female, 61.2% were between the ages of 20-29 years, 53.7% were married, 72.7% had a Bachelor's degree, and 54.9% had 1-5 years of professional experience.Furthermore, 79.2% of the participants reported that they had received training or courses on medication safety, 79.5% reported that medication administration principles were followed in the clinic where they worked, and 76.7% stated that medication administration was performed following the hospital's medication administration rules and procedures (Table 1).The results of the methodological and descriptive stages of the study are provided in the following two sections.

Results of the methodological stage
The scale was translated into Turkish by four translators who were native Turkish speakers and fluent in English.The researchers then combined the four translations into a single form.In the second step, this form was translated back into English by an expert who was not one of the previous translators.
The expert review was conducted by nine nursing instructors and two nurses with master's degrees.The I-CVI ranged from 0.80 to 1.00, and the S-CVI was 0.98.To assess the face validity of the Turkish form, a preliminary application was performed with 20 nurses.To ensure that they were comprehensible in Turkish, the expression "human factors" in the item "Understanding the role of human factors, such as fatigue, that affect medication safety" was changed to "personal factors", and the expression "understanding the role" in "Understanding the role of environmental factors such as workflow, ergonomics, and resources, which affect medication safety" was changed to "understanding the effect".With these adjustments, the scale form adapted to Turkish was finalised.Data from the pilot study were not included in the sample.
The results of CFA are shown in Table 3.The fitness indices of the original scale (model 1) (χ 2 / df = 1921.97/579= 3.32, RMSEA = 0.067, CFI = 0.98) were determined to be at an acceptable level (Fig. 1).However, modification indices were examined, and the original scale was modified sequentially as follows: item 28 and item 31, item 25 and item 31, item 10 and item 11, respectively.The modification of model 2 was achieved by freeing the error terms (permitting correlated errors) of the items without excluding any items (Fig. 2).
For convergent validity, the CRs ranged from 0.68 to 0.79 and were higher than the AVE values (0.40 to 0.60).The correlation between factors ranged from 0.687 to 0.868 (Table 5).Item analyses revealed that the item-total correlations were between 0.46 and 0.77 (Table 4).A statistically significant difference (t: −30.601, p < 0.001) was observed between the mean scores of the groups with the lowest 27% of scores and the highest 27% of scores.
As shown in Table 5, the Cronbach's alpha coefficient of the scale was 0.97.The split-half reliability was 0.912, and the test-retest reliability (ICC) was 0.939.

Result of the descriptive stage
The participants' total mean score of MSCS was 147.81 ± 21.29, indicating a average level of medication safety competence.The lowest score was obtained in the RNP dimension (11.88 ± 2.05 points) and the highest score was obtained in the PCMM dimension (38.21 ± 5.14 points) (Table 5).Table 2 presents the comparison of participants' the of medication safety competence according to their demographic characteristics.
No differences were observed in the participants' the of medication safety competence according to gender and the type of clinic they worked in.However, significant differences were found according to age, marital status, educational level, professional experience, and the type of hospital in which the nurses worked.Participants aged 40 years and older had higher the of medication safety competence than those aged 20-29 years; married participants had higher than single participants; and those with health vocational school and postgraduate degrees had higher than those with undergraduate degrees.In addition, nurses who received training or courses on medication safety, those who thought that the principles of medication administration were followed in the clinic where they worked, and those who thought that medication administration was performed following the hospital's medication administration rules and procedures had higher the of medication safety competence (p < 0.05).

Discussion of the Methodological Stage
This study was conducted to determine the validity and reliability of a Turkish version of the MSCS.This study found that the Turkish version of the MSC scale meets the criteria of language validity, content validity, construct validity, and reliability.The validity and reliability of the scale have also been confirmed in Chinese and Persian [4,6].In this study, the Turkish version of the scale was created using the back translation method for language validity.Then the content validity of the scale was evaluated according to Davis's (1992) technique [13].
Because the CVI values of all items were above 0.80, no items were removed at this stage.CFA was performed to verify construct validity.Two models were analysed: the original scale (model 1) and the final scale (model 2).According to the factor loadings and modification indices of model 1 and model 2, the measurement validity of the Turkish version of the MSCS was confirmed.Thus, no items were removed from the scale at this stage.
The χ 2 /df of the final scale was 3.00; this value is considered acceptable, as it is less than 5 [14].The RMSEA value of 0.062 is an important indicator of the acceptable fit of the final scale.The RMR (0.042) and SRMR (0.057) values showed perfect and acceptable fit, respectively [15].The CFI was above 0.95, indicating perfect fit [16].The NFI and NNFI were also above 0.95, indicating perfect fit [17,18].In CFA, it is recommended that the factor loadings of the items factors should be above 0.50 [10].In this study, the factor loadings of the items were between 0.46 and 0.83 (Table 4).Thus, the fit indices and item factor loadings confirmed the construct validity of the final scale.The AVEs of the factors were higher than 0.50 in all subdimensions except for RNP and MEF.Moreover, the CRs were between 0.68 and 0.79, higher than the  5).These results confirmed the scale's convergent validity.
Finally, item analyses showed that the items in the scale had good discrimination.Similarly, the Chinese version [4], the original scale [5] and the Persian version [6] also reported high factor loadings, acceptable fit indices and CRs above 0.70.In line with these results, it can be said that the scale provides an adequate level of validity.

Reliability
The reliability of the scale was evaluated by calculating split-half reliability, Cronbach's alpha, CR and ICC.Cronbach's alpha value should be at least 0.70 [11,19].In the present study, Cronbach's alpha was 0.97, whereas it was 0.94 in the Chinese version [4], 0.94 in the original scale [5], and 0.96 in the Persian version [6].The CR values reported as more appropriate reliability measures for CFA-based studies [11] are higher than the proposed value of 0.70.These results show that the scale has good internal reliability in samples from different cultures.In this study, the split-half reliability of the scale was 0.912, and the test-retest reliability was 0.939.The split-half reliability of the Chinese version of the scale was 0.671, and the test-retest reliability was 0.703 [4].For the Persian version, the test-retest reliability was also 0.90 [6].These values indicate the stability of the various versions of the scale [20].

Discussion of the descriptive phase
To date, nurses' medication safety competency has generally been examined within the framework of the right principles [21,22] or reporting medication errors [23,24].However, medication safety is a concept that transcends the right principles [3,8], and previous studies measuring nurses' medication safety competency have been insufficient.The medication safety competence scores of the nurses in this study were average.Mohebi et al. (2024) also reported the medication safety competence of nursing students at an average level.These results could indicate that the medication safety competence of nurses and students were adequate but needed further development [25].These results may be explained by the fact that most of the nurses in the study received training or courses on medication safety.Moreover, in recent years, in Turkey and other countries, patient and medication safety issues have been important issues of health policies and    [26].
In this study nurses' the of medication safety competence differ according to age, marital status, education level, professional experience, hospital type, and the types of training or courses on medication safety the nurses have received.More studies investigating nurses' the of medication safety competence are warranted, along with studies assessing differences in the of medication safety competence between nurses with varying demographic characteristics.This study provides strong evidence for the reliability and validity of the scale in Turkish.It is also the first study to determine the medication safety competencies of nurses working in Turkey.
This study presents strong evidence that the Turkish version of the MSCS is valid and reliable among nurses.The medication safety competency levels of the nurses participating in this study were average.The assessment results of the scale provide a reference for nursing administrators to help them formulate educational plans improve the medication safety competence of nurses.

Limitations
One of the strengths of this study is its application of the scale to a large sample.Although the methodological results are important, the adapted scale is specific to nurses in Turkey.However, the results regarding nurses' medication safety competence obtained in the study's second stage provide a substantial contribution to the literature.No funding has been received.

Fig. 1
Fig. 1 CFA results of Model I: standard loadings and error variances

Fig. 2
Fig. 2 CFA results of Model II: standard loadings and error variances

Table 1
The distribution of demographic characteristics of participants

Table 2
Comparison of participants' of medication safety competence according to demographic characteristics

Demographic Characteristics Groups N m ± sd Mean rank Test Value P Difference
[6]ms 10,123,2,29,31,32,34,35); and responsibility in the nursing profession(Items 17,23,36).The scale is a five-point Likert scale.The total score ranges from 36 to 180.Scores between 36 and 75 represent poor medication safety competence, scores between 76 and 130 indicate moderate medication safety competence, and a score of 180 represents high medication safety competence[6].Data were collected through an online survey between February 1 and March 31, 2023.Participants were reached via social media (WhatsApp, Instagram story, etc.
Note: m Mean, sd Standard Deviation, * Mann Whitney U Test **Kruskal Wallis Test of safety problems (

Table 3
CFA results of Model I and Model II: fit indices

Table 4
CFA and item analysis results of the Model II

Table 5
Convergent validity and internal consistency results of the Model II and Mean scores of the participants Note: m (mean), sd (standard deviation), CR (Construct Reliability), AVE (Average Variance Extracted), α (Cronbach's alpha)